The invention broadly relates to grain threshing and is specifically directed to a portable grain sampling device used for threshing grain for sample testing.
As the harvest season approaches, it is common practice for grain farmers to test the moisture content of the growing grain to determine the precise point at which it should be harvested. If it is harvested prematurely, when the moisture content is high, the grain requires drying in a grain drying elevator, which is time consuming and extremely expensive. If harvesting is delayed until the grain is too dry, the grain crop is worth less on the market. To optimize the value of the grain crop, it is therefore necessary to periodically determine the moisture content of the grain and to harvest it at the point at which the grain is properly ripened and therefore capable of maximizing the farmer's monetary return for invested work and expense.
While this concept is easily articulated, it is much more difficult to execute. Currently, grain samples of sufficient quantity to determine moisture content are obtained by operating the farmer's combine at various points in the field. This means that the combine must be transported to the field and operated at various points. For larger grain farms, these distances alone may be quite significant. Further, the combine is a large, complex machine that is slow to transport and quite expensive to operate. It will typically take several hours for the farmer to transport the combine to the field and to operate it at various points to determine whether the grain is ripe for harvest. The problem is compounded significantly if the fields are wet from a recent rain due to the size and weight of the combine, and this may even delay grain sampling beyond the point of optimum harvest.
Our invention has been designed and developed to enable the farmer to quickly and efficiently take grain samples from various points in the grain field without the use of a combine. Specifically, the invention resides in a portable grain sampling device which is relatively small and lightweight, and which can be easily carried by a single person to and into the field for grain sampling and moisture content determination.
In the preferred embodiment, the portable grain sampling device is contained in a metal cabinet or enclosure having a top handle enabling it to be carried in much the same manner as a suitcase. A grain sample collector taking the form of a large cup with an open front and a plurality of forwardly projecting tines enables the farmer to gather several scoops of grain at a particular point in the field and to deposit them in a collection bag.
The sampled grain heads are then fed slowly into the inlet of the portable grain sampling device several at a time. At a first stage, the grain heads, which are in a clustered form, are broken up by passing them through a plurality of relatively moving pins that are disposed transverse to grain movement. Specifically, a first set of transverse pins is carried the cabinet frame and a second set is rotated on a large gear wheel.
The declustered grain sample drops by gravity and is funneled into a unique threshing stage. The threshing stage consists of a stationary vertical surface having a layer of resilient material such as rubber, which is disposed in spaced relation to a spaced, parallel rotating surface that is also resilient and frictional. The rotating surface preferably takes the form of a second relatively large gear wheel the face of which also has a layer (disk) of rubber, and which also drives the first gear wheel. The space between the stationary and rotatable surfaces is adjustable as a function of the type of grain that is being sampled. It has been found that rotating one resilient, frictional surface relative to a stationary surface is highly efficient in breaking up the grain and separating the grain kernels from the chaff. The threshing principle may be utilized on full size threshing equipment including combines. It is possible to accomplish relative movement in different manners, but rotating a large disk relative to a stationary surface is relatively simple and effective.
After threshing, the grain kernels and chaff fall by gravity into a separation stage, consisting of a plurality of angular vanes that are transversely disposed to the downward path of grain movement. The vanes are carried by a frame that is continuously reciprocated or shaken in a sifting manner. A blower within the cabinet having an outlet disposed to the side and below the vanes causes a stream of air to move upwardly through the vanes, lifting the chaff from the vanes and preventing it from falling through. A chaff outlet located in the side of the cabinet allows the separated chaff to be discharged from the device.
The grain kernels are of greater density, and they fall through the vanes into a collection drawer below. The grain sample can then be tested, for example, for moisture content, microbial or fungal disease, protein content, test weight, and other like parameters. A sensor can be contained in the drawer, for example, to enable the farmer to immediately determine the moisture content, or other measurement, of the sampled grain.
The grain sampling device may be operated manually through the use of a hand crank or through an optional electric motor drive mechanism. The motor drive mechanism can be powered by connecting a cable from the farmer's utility vehicle (connected directly to the battery or to the cigarette lighter) and plugged into the sampling device.
This process can be repeated at various points in the grain field until the moisture content is properly determined, enabling the farmer to quickly and easily determine when the grain should be harvested.
Compared with the conventional approach of sampling by combine, the portable grain sampling device represents a significant savings in time and expense. The device is sufficiently portable that it may be easily placed in the farmer's utility vehicle (e.g., pickup truck) and driven to each point at the field. Since the utility vehicle can operate at normal road speed as compared with the slow moving combine, this in itself saves hours of time. As compared to the costs of operating a combine, driving the portable grain sampling device from point to point represents a significant saving of several hundred and perhaps more than a thousand dollars depending on the size of the grain field and the number of points sampled.
The inventive portable grain sampling device will be more fully appreciated from the accompanying description and drawings.